Unger Thomas
Institute of Pharmacology and Toxicology, Charité Hospital, Humboldt University at Berlin, Berlin, Germany.
Am J Cardiol. 2003 May 22;91(10A):28G-34G. doi: 10.1016/s0002-9149(03)00230-3.
The renin-angiotensin system evolved to maintain volume homeostasis and blood pressure and to prevent ischemia during acute volume loss. But in the present age, these mechanisms are redundant, and the clinical significance of angiotensin II results from its pathologic effects, which are mediated by the angiotensin II type 1 (AT(1)) receptor. Activation of AT(1) receptors has been linked to pathologic processes that contribute to atherosclerosis and ischemic events, including oxidative stress, inflammatory processes, low-density lipoprotein cholesterol trafficking, and prothrombotic states. The Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) program will compare the efficacy of the angiotensin II receptor blocker (ARB) telmisartan, the angiotensin-converting enzyme (ACE) inhibitor ramipril, and combination therapy with telmisartan plus ramipril for reducing cardiovascular risk. The ARB telmisartan is distinguished by its long duration of action, which compares favorably with some other ARBs and conventional antihypertensives. Ramipril was shown in the Heart Outcomes Prevention Evaluation (HOPE) study to reduce the risk for myocardial infarction (MI) and other cardiovascular events in patients at high risk for cardiovascular events but without heart failure or a low ejection fraction. The ONTARGET program consists of 2 randomized, double-blind, multicenter international trials: a principal trial, ONTARGET, and a parallel trial, Telmisartan Randomized Assessment Study in ACE-I Intolerant Patients with Cardiovascular Disease (TRANSCEND). The treatment arms for the principal ONTARGET study are telmisartan 80 mg, ramipril 10 mg, and combination therapy with telmisartan 80 mg plus ramipril 10 mg; for the parallel study TRANSCEND, the treatment arms are telmisartan 80 mg and placebo. Both trials will assess cardiovascular outcomes in patients at high risk using the same criteria as that of the HOPE study, with a single exception: the TRANSCEND trial will enroll patients who do not tolerate ACE inhibitor treatment. The primary end points in both ONTARGET and TRANSCEND are death caused by cardiovascular disease, acute MI, stroke, and hospitalization because of congestive heart failure. The secondary end points include newly diagnosed heart failure, revascularization, new-onset type 2 diabetes mellitus, nephropathy, cognitive decrease and dementia, and newly diagnosed atrial fibrillation; these will be used for hypothesis generation.
肾素 - 血管紧张素系统的进化是为了维持容量稳态和血压,并在急性容量丢失期间预防局部缺血。但在当今时代,这些机制是多余的,血管紧张素II的临床意义源于其病理作用,这些作用由1型血管紧张素II(AT(1))受体介导。AT(1)受体的激活与促成动脉粥样硬化和缺血事件的病理过程相关,包括氧化应激、炎症过程、低密度脂蛋白胆固醇转运和血栓前状态。正在进行的替米沙坦单药及与雷米普利联合应用的全球终点试验(ONTARGET)项目将比较血管紧张素II受体阻滞剂(ARB)替米沙坦、血管紧张素转换酶(ACE)抑制剂雷米普利以及替米沙坦加雷米普利联合治疗降低心血管风险的疗效。ARB替米沙坦的特点是作用持续时间长,与其他一些ARB和传统抗高血压药物相比具有优势。在心脏结局预防评估(HOPE)研究中显示,雷米普利可降低心血管事件高危患者(但无心力衰竭或低射血分数)发生心肌梗死(MI)和其他心血管事件的风险。ONTARGET项目包括2项随机、双盲、多中心国际试验:一项主要试验ONTARGET和一项平行试验,即替米沙坦在不耐受ACE-I的心血管疾病患者中的随机评估研究(TRANSCEND)。ONTARGET主要研究的治疗组为替米沙坦80mg、雷米普利10mg以及替米沙坦80mg加雷米普利10mg联合治疗;对于平行研究TRANSCEND,治疗组为替米沙坦80mg和安慰剂。两项试验都将使用与HOPE研究相同的标准评估高危患者的心血管结局,唯一的例外是:TRANSCEND试验将纳入不耐受ACE抑制剂治疗的患者。ONTARGET和TRANSCEND的主要终点是心血管疾病导致的死亡、急性MI、中风以及因充血性心力衰竭住院。次要终点包括新诊断的心力衰竭、血管重建、新发2型糖尿病、肾病、认知减退和痴呆以及新诊断的心房颤动;这些将用于生成假设。